https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117153
--- Comment #7 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-13 branch has been updated by Marek Polacek <mpola...@gcc.gnu.org>: https://gcc.gnu.org/g:988c0b796721d6e8be6a54abb48b695dae972dcf commit r13-9345-g988c0b796721d6e8be6a54abb48b695dae972dcf Author: Marek Polacek <pola...@redhat.com> Date: Mon Nov 25 09:45:13 2024 -0500 c++: ICE with nested anonymous union [PR117153] In a template, for union { union { T d; }; }; build_anon_union_vars crates a malformed COMPONENT_REF: we have no DECL_NAME for the nested anon union so we create something like "object.". Most of the front end doesn't seem to care, but if such a tree gets to potential_constant_expression, it can cause a crash. We can use FIELD directly for the COMPONENT_REF's member. tsubst_stmt should build up a proper one in: if (VAR_P (decl) && !DECL_NAME (decl) && ANON_AGGR_TYPE_P (TREE_TYPE (decl))) /* Anonymous aggregates are a special case. */ finish_anon_union (decl); PR c++/117153 gcc/cp/ChangeLog: * decl2.cc (build_anon_union_vars): Use FIELD for the second operand of a COMPONENT_REF. gcc/testsuite/ChangeLog: * g++.dg/other/anon-union6.C: New test. * g++.dg/other/anon-union7.C: New test. Reviewed-by: Jason Merrill <ja...@redhat.com> (cherry picked from commit 10850f92b2a618ef1b1ad399530943ef4847823d)
